Copper Dry Etching with Cl2 / Ar Plasma Chemistry

Etch rates ⩾5000 Å min −1 were obtained for Cu in electron cyclotron resonance discharges at a sample temperature of 200°C for ion‐neutral ratios ⩾0.02. The rates are a strong function of ion‐neutral ratio, ion flux, and ion energy through the need to have desorption rate faster than the , generation rate in order to avoid formation of a chlorinated selvedge layer. Postetch, in situ plasma cleaning removes most of the chlorine residues and allows creation of clean, anistropic Cu features.